Trial is underway for a former Waipahu High School teacher and coach accused of sexually assaulting a student.

His defense says it’s a case of revenge while prosecutors argue he abused her and her family’s trust.

The teenage victim reportedly told a teacher about the sex assaults while she was on the track team.

Erik Tamura, 37, is on trial for three counts of third-degree sex assault.

Prosecutors say the incidents happened during the victim’s sophomore and junior years at her home and on campus.

“He walks in when she’s showering and says, ‘You shower with your bra and panty on?’ She grabs her towel and runs into the stall, but this teacher, he follows her,” prosecuting attorney Victoria Chang said.

“This is a case about revenge. Teenage revenge,” defense attorney Kenneth Shimozono said. “Even after he did this supposed act, you will hear from witnesses she was hanging out in his classroom her junior year, no problem.”

Tamura is no longer a teacher or coach with the Department of Education.